Appointments Lite Bug

I switched from Appointments+ to Appointments Lite and have since the following issue:

My goal is to have 2 slots per day, each 3 hrs: one 9-12 and one 14-17.
I have 1 service that lasts 180 mins (3 hours).
I set working hours to 9-17, with a break 12-14.
There are no exception dates.

Is: Slot at 9 is bookable, slots at 12, 15 and 18 are displayed, but marked as "busy".
Should: Slot at 9 and 14 should be bookable. No slots at 12, 15, and 18 should be displayed.

When I set the break to 12-13, the following happens:
Is: Slot at 9 is bookable, slot at 12 is also bookable (even though that is a break time, and the service lasts 3 hours!); slots at 15 and 18 are displayed, but marked as "busy".
Should: Slot at 9 should be bookable, 2nd slot at 13 or 14 should be bookable. No slots at 12, 15, or 18 should be displayed.

I consider this a major bug in Appointments Lite, and haven't encountered this in Appointments+ when I tested it 2 hours ago.